Boiler.



Patented 00h29, 1918P APPLICATION FILED SEPT. l l. |9IT.

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FREDERICK B. Al-IIBBARD, OF PHILADELPHIA, PENNSYLVANIA.

BOILER.

Specification of Letters Patent.

Patented @et 29, 1918.

Application filed September 11, 1917.l Serial No. 190,706.

To all whom t mayconcem:

Be it known that I, FREDERICK B. HIB- BARD, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia, State of Pennsylvania, have invented a new and useful Boiler, of which the following` is a specification.

My invention relates to improvements in horizontal internally tired return tubular steam boilers, and especially to improve ments in the construction of the ire box and the arrangement of the tubes.

The object of the invention is to so con` struct the re box as to have the effect of a Dutch oven to conserve or store the heat and to prevent, in a great measure, the formation of smoke when fresh coal is thrown on the grate.

The invention comprises means for simplifying the construction of the tire box whereby the walls are protected without a tire brick lining and the heat of combus tion is communicated directly through the said walls to the water and steam of the boiler. y

The improved construction also permits the outgoing tubes of the boiler to be placed below the level of the grate bars and close to the bottom of the boiler, so as to cause a rapid and complete circulation of the waH ter therein. Y

Referring to the drawings, which illustrate merely by way of example, suitable means for the embodiment of my invention- Figure 1 is a longitudinal vertical section. 4

Fig. 2 is a vertical cross section on line 2 2 of Fig. l, on an enlarged scale.

Similar numerals refer to similar parts throughout the several views. l is the shell of the boiler, 2 is the smoke stack fitted with the usual damper 3. 4 are the outgoing tubes, 5 the return tubes, 6 the grate, 7 the bridge wall, 8 the top and the arch of fire brick which also divides the passage of the outgoing from return of gas. 9 indicates the lire box, and 10 and 11 are the front and rear tube sheets.

The grate 6, the bridge wall 7 and .the top 8 of the iire box 9 are all located w1thin the shell 15 which forms, with the shell 1 of the boiler, the water jacket 16. The heat from the lire carried on `the grate .heats the top 8 of the fire box which radiates this heat downwardly as do the walls of a Dutch oven, and to a great extent prevents the formation of smoke when fresh fuel is thrown upon the grate for the reason that it prevents any considerable chilling of the tire box when the fresh fuel is introduced.

The rear end 12 of the top wall 8 of the ire box has an inclined formation 12 ex ltending to a point substantially below the top of the bridge wall 7, where it engages the forward tube sheet 10. The bridge wall 7 is located some little distance in front of this inclined extension 12. These two parts 7 and 12 together form a passage for the heat and products of combustion to the our.- going tubes 4.

It will be noted that by the construction shown, it is possible to locate the lower row of outgoing tubes 4c close to the bottom of the shell 1, thus insuring as complete as possible the circulation throughout the whole whole diameter of the boiler.

. The heat and products of combustion pass through the outgoing tubes 4t to the space 13 between rear tube sheet 11, to the rear 'end 14 of the boiler, and thence to and through the return tubes 5 to the stack 2.

It will be noted that the inclined formation 12 of arch 8, in coperation with brid `e wall 7, conducts the hotgases downward y from the top of the re box to the tubes 4, and the same inclined formation 12 serves to direct the hot gases from the tubes 5 sharply upward to the shell 15, which forms with the outer boiler shell 1, a continuation of the steam space of the boiler.

It will be noted from an inspection of Fig. 2 that this inner shell 15 below the ire arch 5 needs no fire brick protection, since the space between shells 1 and 15 is iilled with the boiler water. This serves the double purpose of protecting the inner shell 15 from burning out, and of communicating the heat of combustion directly through the wall 15 to the water contiguous thereto. Thus is secured additional simplicity of construction, economy of fuel and efficiency in steam generation.

What I claim is 1. In a horizontal internally tired return tubular steam boiler, the combination of a shell having front and rear tube sheets, tubes fitted therein, a fire box at one end of said shell comprising an inner shell spaced within the first mentioned shell and forming a water and steam `jacket about the lire box, an arch and bridge wall for said lire box of refiactorY material, the rear part of said arch having an inclined formation extending to a point substantially below the top of the bridge wall, and forming with the bridge Wall a restricted passage Within the first mentioned shell and form-A,

ing a water and steam jacket about the lire box, anarch and bridge Wall for said lire box of refractory material, the arch having a horizontal extension forming a narrow horizontal passage from the return tubes to the smoke stack, and the rear part of said arch having an inclined formation extending to a point substantially below the top of the bridge Wall, and forming with the bridge Wall a passage from the top of the lire box to the outgoing tubes, the upper side of said inclined formation also arranged sharply to deect the products of oonibustion from the return tubes, to the top of the fire box and said horizontal passage.

FREDERICK B. HIBBARD.

Copies of this; patent may be obtained for five cents each, byaddressing' the Commissioner of Patents,

Washington, D. C. 

